It's only a Fourth Amendment violation if the force used was no objectively reasonable under the circumstances, and that is evaluated giving the police the benefit of the doubt, not 20-20 hindsight, under the Supreme Court's decision in Graham v. Connor, quite a few years ago.

Even if you can prove a violation of your rights, if it turns out that the rights you're enforcing weren't "clearly established" at the time, the police can claim what's called qualified immunity, and you won't get paid.

These cases are difficult for experienced trial attorneys.  Without knowing a lot more about the incident, it's impossible to tell you that this is worth pursuing.